Just to clarify...that is a grep find/change.
Use GREP. With a GREP search, you can search for lots more wildcard characters than the regular search-and-replace (with which it's also possible but requires multiple searches).
Enter this into the Find line of GREP
and this into the Replace With line
In essence, this looks for the pound sign, followed by one or more digits, and optionally followed by a period plus exactly two more digits. That should cover most of your prices. If not, check if they have a space after the pound, or possibly a comma in the number - for example, "£ 10,456.45" will not be found by this expression. Also, if there are typos in a price - say, someone entered "£19.9" and forgot the second decimal - this expression will not change it. So after running, check for leftovers.
.. which you don't need to do by eye! Search (but do not replace!) for this
and you will find every pound that is not followed by the zeroed-out price. You must not use this with Replace because (1) it will only remove the pound symbol itself, and (2) there may be good reasons for a pound not to be followed by a price ("all prices are in English ££"), and (3) you'll need to manually take care of possible errors and misses of the first GREP on a case-by-case base.
WOW! Amazing - thanks guys! This has helped me out massively and saved me loads of time!
Thank you once again!
Have a good day